The Tor Browser: mobile/android/base/gfx/GeckoLayerClient.java@fc2d59ddac77 (annotated)

mobile/android/base/gfx/GeckoLayerClient.java@fc2d59ddac77 (annotated)

mobile/android/base/gfx/GeckoLayerClient.java

Wed, 31 Dec 2014 07:22:50 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 07:22:50 +0100
branch: TOR_BUG_3246
changeset 4: fc2d59ddac77
permissions: -rw-r--r--

Correct previous dual key logic pending first delivery installment.

 /* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*-
  * This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 package org.mozilla.gecko.gfx;
 import org.mozilla.gecko.GeckoAppShell;
 import org.mozilla.gecko.GeckoEvent;
 import org.mozilla.gecko.gfx.LayerView.DrawListener;
 import org.mozilla.gecko.Tab;
 import org.mozilla.gecko.Tabs;
 import org.mozilla.gecko.ZoomConstraints;
 import org.mozilla.gecko.mozglue.RobocopTarget;
 import org.mozilla.gecko.mozglue.generatorannotations.WrapElementForJNI;
 import org.mozilla.gecko.EventDispatcher;
 import org.mozilla.gecko.util.FloatUtils;
 import android.content.Context;
 import android.graphics.PointF;
 import android.graphics.RectF;
 import android.os.SystemClock;
 import android.util.DisplayMetrics;
 import android.util.Log;
 import java.util.ArrayList;
 import java.util.List;
 class GeckoLayerClient implements LayerView.Listener, PanZoomTarget
 {
     private static final String LOGTAG = "GeckoLayerClient";
     private LayerRenderer mLayerRenderer;
     private boolean mLayerRendererInitialized;
     private Context mContext;
     private IntSize mScreenSize;
     private IntSize mWindowSize;
     private DisplayPortMetrics mDisplayPort;
     private boolean mRecordDrawTimes;
     private final DrawTimingQueue mDrawTimingQueue;
     private VirtualLayer mRootLayer;
     /* The Gecko viewport as per the UI thread. Must be touched only on the UI thread.
      * If any events being sent to Gecko that are relative to the Gecko viewport position,
      * they must (a) be relative to this viewport, and (b) be sent on the UI thread to
      * avoid races. As long as these two conditions are satisfied, and the events being
      * sent to Gecko are processed in FIFO order, the events will properly be relative
      * to the Gecko viewport position. Note that if Gecko updates its viewport independently,
      * we get notified synchronously and also update this on the UI thread.
      */
     private ImmutableViewportMetrics mGeckoViewport;
     /*
      * The viewport metrics being used to draw the current frame. This is only
      * accessed by the compositor thread, and so needs no synchronisation.
      */
     private ImmutableViewportMetrics mFrameMetrics;
     private List<DrawListener> mDrawListeners;
     /* Used as temporaries by syncViewportInfo */
     private final ViewTransform mCurrentViewTransform;
     private final RectF mCurrentViewTransformMargins;
     /* Used as the return value of progressiveUpdateCallback */
     private final ProgressiveUpdateData mProgressiveUpdateData;
     private DisplayPortMetrics mProgressiveUpdateDisplayPort;
     private boolean mLastProgressiveUpdateWasLowPrecision;
     private boolean mProgressiveUpdateWasInDanger;
     private boolean mForceRedraw;
     /* The current viewport metrics.
      * This is volatile so that we can read and write to it from different threads.
      * We avoid synchronization to make getting the viewport metrics from
      * the compositor as cheap as possible. The viewport is immutable so
      * we don't need to worry about anyone mutating it while we're reading from it.
      * Specifically:
      * 1) reading mViewportMetrics from any thread is fine without synchronization
      * 2) writing to mViewportMetrics requires synchronizing on the layer controller object
      * 3) whenver reading multiple fields from mViewportMetrics without synchronization (i.e. in
      *    case 1 above) you should always frist grab a local copy of the reference, and then use
      *    that because mViewportMetrics might get reassigned in between reading the different
      *    fields. */
     private volatile ImmutableViewportMetrics mViewportMetrics;
     private LayerView.OnMetricsChangedListener mViewportChangeListener;
     private ZoomConstraints mZoomConstraints;
     private boolean mGeckoIsReady;
     private final PanZoomController mPanZoomController;
     private final LayerMarginsAnimator mMarginsAnimator;
     private LayerView mView;
     /* This flag is true from the time that browser.js detects a first-paint is about to start,
      * to the time that we receive the first-paint composite notification from the compositor.
      * Note that there is a small race condition with this; if there are two paints that both
      * have the first-paint flag set, and the second paint happens concurrently with the
      * composite for the first paint, then this flag may be set to true prematurely. Fixing this
      * is possible but risky; see https://bugzilla.mozilla.org/show_bug.cgi?id=797615#c751
      */
     private volatile boolean mContentDocumentIsDisplayed;
     public GeckoLayerClient(Context context, LayerView view, EventDispatcher eventDispatcher) {
         // we can fill these in with dummy values because they are always written
         // to before being read
         mContext = context;
         mScreenSize = new IntSize(0, 0);
         mWindowSize = new IntSize(0, 0);
         mDisplayPort = new DisplayPortMetrics();
         mRecordDrawTimes = true;
         mDrawTimingQueue = new DrawTimingQueue();
         mCurrentViewTransform = new ViewTransform(0, 0, 1);
         mCurrentViewTransformMargins = new RectF();
         mProgressiveUpdateData = new ProgressiveUpdateData();
         mProgressiveUpdateDisplayPort = new DisplayPortMetrics();
         mLastProgressiveUpdateWasLowPrecision = false;
         mProgressiveUpdateWasInDanger = false;
         mForceRedraw = true;
         DisplayMetrics displayMetrics = context.getResources().getDisplayMetrics();
         mViewportMetrics = new ImmutableViewportMetrics(displayMetrics)
                            .setViewportSize(view.getWidth(), view.getHeight());
         mZoomConstraints = new ZoomConstraints(false);
         Tab tab = Tabs.getInstance().getSelectedTab();
         if (tab != null) {
             mZoomConstraints = tab.getZoomConstraints();
             mViewportMetrics = mViewportMetrics.setIsRTL(tab.getIsRTL());
         }
         mFrameMetrics = mViewportMetrics;
         mDrawListeners = new ArrayList<DrawListener>();
         mPanZoomController = PanZoomController.Factory.create(this, view, eventDispatcher);
         mMarginsAnimator = new LayerMarginsAnimator(this, view);
         mView = view;
         mView.setListener(this);
         mContentDocumentIsDisplayed = true;
     }
     public void setOverscrollHandler(final Overscroll listener) {
         mPanZoomController.setOverscrollHandler(listener);
     }
     /** Attaches to root layer so that Gecko appears. */
     public void notifyGeckoReady() {
         mGeckoIsReady = true;
         mRootLayer = new VirtualLayer(new IntSize(mView.getWidth(), mView.getHeight()));
         mLayerRenderer = mView.getRenderer();
         sendResizeEventIfNecessary(true);
         DisplayPortCalculator.initPrefs();
         // Gecko being ready is one of the two conditions (along with having an available
         // surface) that cause us to create the compositor. So here, now that we know gecko
         // is ready, call updateCompositor() to see if we can actually do the creation.
         // This needs to run on the UI thread so that the surface validity can't change on
         // us while we're in the middle of creating the compositor.
         mView.post(new Runnable() {
             @Override
             public void run() {
                 mView.getGLController().updateCompositor();
             }
         });
     }
     public void destroy() {
         mPanZoomController.destroy();
         mMarginsAnimator.destroy();
         mDrawListeners.clear();
     }
     /**
      * Returns true if this client is fine with performing a redraw operation or false if it
      * would prefer that the action didn't take place.
      */
     private boolean getRedrawHint() {
         if (mForceRedraw) {
             mForceRedraw = false;
             return true;
         }
         if (!mPanZoomController.getRedrawHint()) {
             return false;
         }
         return DisplayPortCalculator.aboutToCheckerboard(mViewportMetrics,
                 mPanZoomController.getVelocityVector(), mDisplayPort);
     }
     Layer getRoot() {
         return mGeckoIsReady ? mRootLayer : null;
     }
     public LayerView getView() {
         return mView;
     }
     public FloatSize getViewportSize() {
         return mViewportMetrics.getSize();
     }
     /**
      * The view calls this function to indicate that the viewport changed size. It must hold the
      * monitor while calling it.
      *
      * TODO: Refactor this to use an interface. Expose that interface only to the view and not
      * to the layer client. That way, the layer client won't be tempted to call this, which might
      * result in an infinite loop.
      */
     void setViewportSize(int width, int height) {
         mViewportMetrics = mViewportMetrics.setViewportSize(width, height);
         if (mGeckoIsReady) {
             // here we send gecko a resize message. The code in browser.js is responsible for
             // picking up on that resize event, modifying the viewport as necessary, and informing
             // us of the new viewport.
             sendResizeEventIfNecessary(true);
             // the following call also sends gecko a message, which will be processed after the resize
             // message above has updated the viewport. this message ensures that if we have just put
             // focus in a text field, we scroll the content so that the text field is in view.
             GeckoAppShell.viewSizeChanged();
         }
     }
     PanZoomController getPanZoomController() {
         return mPanZoomController;
     }
     LayerMarginsAnimator getLayerMarginsAnimator() {
         return mMarginsAnimator;
     }
     /* Informs Gecko that the screen size has changed. */
     private void sendResizeEventIfNecessary(boolean force) {
         DisplayMetrics metrics = mContext.getResources().getDisplayMetrics();
         IntSize newScreenSize = new IntSize(metrics.widthPixels, metrics.heightPixels);
         IntSize newWindowSize = new IntSize(mView.getWidth(), mView.getHeight());
         boolean screenSizeChanged = !mScreenSize.equals(newScreenSize);
         boolean windowSizeChanged = !mWindowSize.equals(newWindowSize);
         if (!force && !screenSizeChanged && !windowSizeChanged) {
             return;
         }
         mScreenSize = newScreenSize;
         mWindowSize = newWindowSize;
         if (screenSizeChanged) {
             Log.d(LOGTAG, "Screen-size changed to " + mScreenSize);
         }
         if (windowSizeChanged) {
             Log.d(LOGTAG, "Window-size changed to " + mWindowSize);
         }
         GeckoEvent event = GeckoEvent.createSizeChangedEvent(mWindowSize.width, mWindowSize.height,
                                                              mScreenSize.width, mScreenSize.height);
         GeckoAppShell.sendEventToGecko(event);
         GeckoAppShell.sendEventToGecko(GeckoEvent.createBroadcastEvent("Window:Resize", ""));
     }
     /** Sets the current page rect. You must hold the monitor while calling this. */
     private void setPageRect(RectF rect, RectF cssRect) {
         // Since the "rect" is always just a multiple of "cssRect" we don't need to
         // check both; this function assumes that both "rect" and "cssRect" are relative
         // the zoom factor in mViewportMetrics.
         if (mViewportMetrics.getCssPageRect().equals(cssRect))
             return;
         mViewportMetrics = mViewportMetrics.setPageRect(rect, cssRect);
         // Page size is owned by the layer client, so no need to notify it of
         // this change.
         post(new Runnable() {
             @Override
             public void run() {
                 mPanZoomController.pageRectUpdated();
                 mView.requestRender();
             }
         });
     }
     /**
      * Derives content document fixed position margins/fixed layer margins from
      * the view margins in the given metrics object.
      */
     private void getFixedMargins(ImmutableViewportMetrics metrics, RectF fixedMargins) {
         fixedMargins.left = 0;
         fixedMargins.top = 0;
         fixedMargins.right = 0;
         fixedMargins.bottom = 0;
         // The maximum margins are determined by the scrollable area of the page.
         float maxMarginWidth = Math.max(0, metrics.getPageWidth() - metrics.getWidthWithoutMargins());
         float maxMarginHeight = Math.max(0, metrics.getPageHeight() - metrics.getHeightWithoutMargins());
         // If the margins can't fully hide, they're pinned on - in which case,
         // fixed margins should always be zero.
         if (maxMarginWidth < metrics.marginLeft + metrics.marginRight) {
           maxMarginWidth = 0;
         }
         if (maxMarginHeight < metrics.marginTop + metrics.marginBottom) {
           maxMarginHeight = 0;
         }
         PointF offset = metrics.getMarginOffset();
         RectF overscroll = metrics.getOverscroll();
         if (offset.x >= 0) {
             fixedMargins.right = Math.max(0, Math.min(offset.x - overscroll.right, maxMarginWidth));
         } else {
             fixedMargins.left = Math.max(0, Math.min(-offset.x - overscroll.left, maxMarginWidth));
         }
         if (offset.y >= 0) {
             fixedMargins.bottom = Math.max(0, Math.min(offset.y - overscroll.bottom, maxMarginHeight));
         } else {
             fixedMargins.top = Math.max(0, Math.min(-offset.y - overscroll.top, maxMarginHeight));
         }
         // Adjust for overscroll. If we're overscrolled on one side, add that
         // distance to the margins of the other side (limiting to the maximum
         // margin size calculated above).
         if (overscroll.left > 0) {
             fixedMargins.right = Math.min(maxMarginWidth - fixedMargins.left,
                                           fixedMargins.right + overscroll.left);
         } else if (overscroll.right > 0) {
             fixedMargins.left = Math.min(maxMarginWidth - fixedMargins.right,
                                          fixedMargins.left + overscroll.right);
         }
         if (overscroll.top > 0) {
             fixedMargins.bottom = Math.min(maxMarginHeight - fixedMargins.top,
                                            fixedMargins.bottom + overscroll.top);
         } else if (overscroll.bottom > 0) {
             fixedMargins.top = Math.min(maxMarginHeight - fixedMargins.bottom,
                                         fixedMargins.top + overscroll.bottom);
         }
     }
     private void adjustViewport(DisplayPortMetrics displayPort) {
         ImmutableViewportMetrics metrics = getViewportMetrics();
         ImmutableViewportMetrics clampedMetrics = metrics.clamp();
         RectF margins = new RectF();
         getFixedMargins(metrics, margins);
         clampedMetrics = clampedMetrics.setMargins(
             margins.left, margins.top, margins.right, margins.bottom);
         if (displayPort == null) {
             displayPort = DisplayPortCalculator.calculate(metrics, mPanZoomController.getVelocityVector());
         }
         mDisplayPort = displayPort;
         mGeckoViewport = clampedMetrics;
         if (mRecordDrawTimes) {
             mDrawTimingQueue.add(displayPort);
         }
         GeckoAppShell.sendEventToGecko(GeckoEvent.createViewportEvent(clampedMetrics, displayPort));
     }
     /** Aborts any pan/zoom animation that is currently in progress. */
     private void abortPanZoomAnimation() {
         if (mPanZoomController != null) {
             post(new Runnable() {
                 @Override
                 public void run() {
                     mPanZoomController.abortAnimation();
                 }
             });
         }
     }
     /**
      * The different types of Viewport messages handled. All viewport events
      * expect a display-port to be returned, but can handle one not being
      * returned.
      */
     private enum ViewportMessageType {
         UPDATE,       // The viewport has changed and should be entirely updated
         PAGE_SIZE     // The viewport's page-size has changed
     }
     /** Viewport message handler. */
     private DisplayPortMetrics handleViewportMessage(ImmutableViewportMetrics messageMetrics, ViewportMessageType type) {
         synchronized (getLock()) {
             ImmutableViewportMetrics newMetrics;
             ImmutableViewportMetrics oldMetrics = getViewportMetrics();
             switch (type) {
             default:
             case UPDATE:
                 // Keep the old viewport size
                 newMetrics = messageMetrics.setViewportSize(oldMetrics.getWidth(), oldMetrics.getHeight());
                 if (!oldMetrics.fuzzyEquals(newMetrics)) {
                     abortPanZoomAnimation();
                 }
                 break;
             case PAGE_SIZE:
                 // adjust the page dimensions to account for differences in zoom
                 // between the rendered content (which is what Gecko tells us)
                 // and our zoom level (which may have diverged).
                 float scaleFactor = oldMetrics.zoomFactor / messageMetrics.zoomFactor;
                 newMetrics = oldMetrics.setPageRect(RectUtils.scale(messageMetrics.getPageRect(), scaleFactor), messageMetrics.getCssPageRect());
                 break;
             }
             // Update the Gecko-side viewport metrics. Make sure to do this
             // before modifying the metrics below.
             final ImmutableViewportMetrics geckoMetrics = newMetrics.clamp();
             post(new Runnable() {
                 @Override
                 public void run() {
                     mGeckoViewport = geckoMetrics;
                 }
             });
             setViewportMetrics(newMetrics, type == ViewportMessageType.UPDATE);
             mDisplayPort = DisplayPortCalculator.calculate(getViewportMetrics(), null);
         }
         return mDisplayPort;
     }
     @WrapElementForJNI
     DisplayPortMetrics getDisplayPort(boolean pageSizeUpdate, boolean isBrowserContentDisplayed, int tabId, ImmutableViewportMetrics metrics) {
         Tabs tabs = Tabs.getInstance();
         if (isBrowserContentDisplayed && tabs.isSelectedTabId(tabId)) {
             // for foreground tabs, send the viewport update unless the document
             // displayed is different from the content document. In that case, just
             // calculate the display port.
             return handleViewportMessage(metrics, pageSizeUpdate ? ViewportMessageType.PAGE_SIZE : ViewportMessageType.UPDATE);
         } else {
             // for background tabs, request a new display port calculation, so that
             // when we do switch to that tab, we have the correct display port and
             // don't need to draw twice (once to allow the first-paint viewport to
             // get to java, and again once java figures out the display port).
             return DisplayPortCalculator.calculate(metrics, null);
         }
     }
     @WrapElementForJNI
     void contentDocumentChanged() {
         mContentDocumentIsDisplayed = false;
     }
     @WrapElementForJNI
     boolean isContentDocumentDisplayed() {
         return mContentDocumentIsDisplayed;
     }
     // This is called on the Gecko thread to determine if we're still interested
     // in the update of this display-port to continue. We can return true here
     // to abort the current update and continue with any subsequent ones. This
     // is useful for slow-to-render pages when the display-port starts lagging
     // behind enough that continuing to draw it is wasted effort.
     @WrapElementForJNI(allowMultithread = true)
     public ProgressiveUpdateData progressiveUpdateCallback(boolean aHasPendingNewThebesContent,
                                                            float x, float y, float width, float height,
                                                            float resolution, boolean lowPrecision) {
         // Reset the checkerboard risk flag when switching to low precision
         // rendering.
         if (lowPrecision && !mLastProgressiveUpdateWasLowPrecision) {
             // Skip low precision rendering until we're at risk of checkerboarding.
             if (!mProgressiveUpdateWasInDanger) {
                 mProgressiveUpdateData.abort = true;
                 return mProgressiveUpdateData;
             }
             mProgressiveUpdateWasInDanger = false;
         }
         mLastProgressiveUpdateWasLowPrecision = lowPrecision;
         // Grab a local copy of the last display-port sent to Gecko and the
         // current viewport metrics to avoid races when accessing them.
         DisplayPortMetrics displayPort = mDisplayPort;
         ImmutableViewportMetrics viewportMetrics = mViewportMetrics;
         mProgressiveUpdateData.setViewport(viewportMetrics);
         mProgressiveUpdateData.abort = false;
         // Always abort updates if the resolution has changed. There's no use
         // in drawing at the incorrect resolution.
         if (!FloatUtils.fuzzyEquals(resolution, viewportMetrics.zoomFactor)) {
             Log.d(LOGTAG, "Aborting draw due to resolution change: " + resolution + " != " + viewportMetrics.zoomFactor);
             mProgressiveUpdateData.abort = true;
             return mProgressiveUpdateData;
         }
         // Store the high precision displayport for comparison when doing low
         // precision updates.
         if (!lowPrecision) {
             if (!FloatUtils.fuzzyEquals(resolution, mProgressiveUpdateDisplayPort.resolution) ||
                 !FloatUtils.fuzzyEquals(x, mProgressiveUpdateDisplayPort.getLeft()) ||
                 !FloatUtils.fuzzyEquals(y, mProgressiveUpdateDisplayPort.getTop()) ||
                 !FloatUtils.fuzzyEquals(x + width, mProgressiveUpdateDisplayPort.getRight()) ||
                 !FloatUtils.fuzzyEquals(y + height, mProgressiveUpdateDisplayPort.getBottom())) {
                 mProgressiveUpdateDisplayPort =
                     new DisplayPortMetrics(x, y, x+width, y+height, resolution);
             }
         }
         // If we're not doing low precision draws and we're about to
         // checkerboard, enable low precision drawing.
         if (!lowPrecision && !mProgressiveUpdateWasInDanger) {
             if (DisplayPortCalculator.aboutToCheckerboard(viewportMetrics,
                   mPanZoomController.getVelocityVector(), mProgressiveUpdateDisplayPort)) {
                 mProgressiveUpdateWasInDanger = true;
             }
         }
         // XXX All sorts of rounding happens inside Gecko that becomes hard to
         //     account exactly for. Given we align the display-port to tile
         //     boundaries (and so they rarely vary by sub-pixel amounts), just
         //     check that values are within a couple of pixels of the
         //     display-port bounds.
         // Never abort drawing if we can't be sure we've sent a more recent
         // display-port. If we abort updating when we shouldn't, we can end up
         // with blank regions on the screen and we open up the risk of entering
         // an endless updating cycle.
         if (Math.abs(displayPort.getLeft() - mProgressiveUpdateDisplayPort.getLeft()) <= 2 &&
             Math.abs(displayPort.getTop() - mProgressiveUpdateDisplayPort.getTop()) <= 2 &&
             Math.abs(displayPort.getBottom() - mProgressiveUpdateDisplayPort.getBottom()) <= 2 &&
             Math.abs(displayPort.getRight() - mProgressiveUpdateDisplayPort.getRight()) <= 2) {
             return mProgressiveUpdateData;
         }
         // Abort updates when the display-port no longer contains the visible
         // area of the page (that is, the viewport cropped by the page
         // boundaries).
         // XXX This makes the assumption that we never let the visible area of
         //     the page fall outside of the display-port.
         if (Math.max(viewportMetrics.viewportRectLeft, viewportMetrics.pageRectLeft) + 1 < x ||
             Math.max(viewportMetrics.viewportRectTop, viewportMetrics.pageRectTop) + 1 < y ||
             Math.min(viewportMetrics.viewportRectRight, viewportMetrics.pageRectRight) - 1 > x + width ||
             Math.min(viewportMetrics.viewportRectBottom, viewportMetrics.pageRectBottom) - 1 > y + height) {
             Log.d(LOGTAG, "Aborting update due to viewport not in display-port");
             mProgressiveUpdateData.abort = true;
             // Enable low-precision drawing, as we're likely to be in danger if
             // this situation has been encountered.
             mProgressiveUpdateWasInDanger = true;
             return mProgressiveUpdateData;
         }
         // Abort drawing stale low-precision content if there's a more recent
         // display-port in the pipeline.
         if (lowPrecision && !aHasPendingNewThebesContent) {
           mProgressiveUpdateData.abort = true;
         }
         return mProgressiveUpdateData;
     }
     void setZoomConstraints(ZoomConstraints constraints) {
         mZoomConstraints = constraints;
     }
     void setIsRTL(boolean aIsRTL) {
         synchronized (getLock()) {
             ImmutableViewportMetrics newMetrics = getViewportMetrics().setIsRTL(aIsRTL);
             setViewportMetrics(newMetrics, false);
         }
     }
     /** The compositor invokes this function just before compositing a frame where the document
       * is different from the document composited on the last frame. In these cases, the viewport
       * information we have in Java is no longer valid and needs to be replaced with the new
       * viewport information provided. setPageRect will never be invoked on the same frame that
       * this function is invoked on; and this function will always be called prior to syncViewportInfo.
       */
     @WrapElementForJNI(allowMultithread = true)
     public void setFirstPaintViewport(float offsetX, float offsetY, float zoom,
             float cssPageLeft, float cssPageTop, float cssPageRight, float cssPageBottom) {
         synchronized (getLock()) {
             ImmutableViewportMetrics currentMetrics = getViewportMetrics();
             Tab tab = Tabs.getInstance().getSelectedTab();
             RectF cssPageRect = new RectF(cssPageLeft, cssPageTop, cssPageRight, cssPageBottom);
             RectF pageRect = RectUtils.scaleAndRound(cssPageRect, zoom);
             final ImmutableViewportMetrics newMetrics = currentMetrics
                 .setViewportOrigin(offsetX, offsetY)
                 .setZoomFactor(zoom)
                 .setPageRect(pageRect, cssPageRect)
                 .setIsRTL(tab.getIsRTL());
             // Since we have switched to displaying a different document, we need to update any
             // viewport-related state we have lying around. This includes mGeckoViewport and
             // mViewportMetrics. Usually this information is updated via handleViewportMessage
             // while we remain on the same document.
             post(new Runnable() {
                 @Override
                 public void run() {
                     mGeckoViewport = newMetrics;
                 }
             });
             setViewportMetrics(newMetrics);
             mView.setBackgroundColor(tab.getBackgroundColor());
             setZoomConstraints(tab.getZoomConstraints());
             // At this point, we have just switched to displaying a different document than we
             // we previously displaying. This means we need to abort any panning/zooming animations
             // that are in progress and send an updated display port request to browser.js as soon
             // as possible. The call to PanZoomController.abortAnimation accomplishes this by calling the
             // forceRedraw function, which sends the viewport to gecko. The display port request is
             // actually a full viewport update, which is fine because if browser.js has somehow moved to
             // be out of sync with this first-paint viewport, then we force them back in sync.
             abortPanZoomAnimation();
             // Indicate that the document is about to be composited so the
             // LayerView background can be removed.
             if (mView.getPaintState() == LayerView.PAINT_START) {
                 mView.setPaintState(LayerView.PAINT_BEFORE_FIRST);
             }
         }
         DisplayPortCalculator.resetPageState();
         mDrawTimingQueue.reset();
         mContentDocumentIsDisplayed = true;
     }
     /** The compositor invokes this function whenever it determines that the page rect
       * has changed (based on the information it gets from layout). If setFirstPaintViewport
       * is invoked on a frame, then this function will not be. For any given frame, this
       * function will be invoked before syncViewportInfo.
       */
     @WrapElementForJNI(allowMultithread = true)
     public void setPageRect(float cssPageLeft, float cssPageTop, float cssPageRight, float cssPageBottom) {
         synchronized (getLock()) {
             RectF cssPageRect = new RectF(cssPageLeft, cssPageTop, cssPageRight, cssPageBottom);
             float ourZoom = getViewportMetrics().zoomFactor;
             setPageRect(RectUtils.scale(cssPageRect, ourZoom), cssPageRect);
             // Here the page size of the document has changed, but the document being displayed
             // is still the same. Therefore, we don't need to send anything to browser.js; any
             // changes we need to make to the display port will get sent the next time we call
             // adjustViewport().
         }
     }
     /** The compositor invokes this function on every frame to figure out what part of the
       * page to display, and to inform Java of the current display port. Since it is called
       * on every frame, it needs to be ultra-fast.
       * It avoids taking any locks or allocating any objects. We keep around a
       * mCurrentViewTransform so we don't need to allocate a new ViewTransform
       * everytime we're called. NOTE: we might be able to return a ImmutableViewportMetrics
       * which would avoid the copy into mCurrentViewTransform.
       */
     @WrapElementForJNI(allowMultithread = true)
     public ViewTransform syncViewportInfo(int x, int y, int width, int height, float resolution, boolean layersUpdated) {
         // getViewportMetrics is thread safe so we don't need to synchronize.
         // We save the viewport metrics here, so we later use it later in
         // createFrame (which will be called by nsWindow::DrawWindowUnderlay on
         // the native side, by the compositor). The viewport
         // metrics can change between here and there, as it's accessed outside
         // of the compositor thread.
         mFrameMetrics = getViewportMetrics();
         mCurrentViewTransform.x = mFrameMetrics.viewportRectLeft;
         mCurrentViewTransform.y = mFrameMetrics.viewportRectTop;
         mCurrentViewTransform.scale = mFrameMetrics.zoomFactor;
         // Adjust the fixed layer margins so that overscroll subtracts from them.
         getFixedMargins(mFrameMetrics, mCurrentViewTransformMargins);
         mCurrentViewTransform.fixedLayerMarginLeft = mCurrentViewTransformMargins.left;
         mCurrentViewTransform.fixedLayerMarginTop = mCurrentViewTransformMargins.top;
         mCurrentViewTransform.fixedLayerMarginRight = mCurrentViewTransformMargins.right;
         mCurrentViewTransform.fixedLayerMarginBottom = mCurrentViewTransformMargins.bottom;
         // Offset the view transform so that it renders in the correct place.
         PointF offset = mFrameMetrics.getMarginOffset();
         mCurrentViewTransform.offsetX = offset.x;
         mCurrentViewTransform.offsetY = offset.y;
         mRootLayer.setPositionAndResolution(
             Math.round(x + mCurrentViewTransform.offsetX),
             Math.round(y + mCurrentViewTransform.offsetY),
             Math.round(x + width + mCurrentViewTransform.offsetX),
             Math.round(y + height + mCurrentViewTransform.offsetY),
             resolution);
         if (layersUpdated && mRecordDrawTimes) {
             // If we got a layers update, that means a draw finished. Check to see if the area drawn matches
             // one of our requested displayports; if it does calculate the draw time and notify the
             // DisplayPortCalculator
             DisplayPortMetrics drawn = new DisplayPortMetrics(x, y, x + width, y + height, resolution);
             long time = mDrawTimingQueue.findTimeFor(drawn);
             if (time >= 0) {
                 long now = SystemClock.uptimeMillis();
                 time = now - time;
                 mRecordDrawTimes = DisplayPortCalculator.drawTimeUpdate(time, width * height);
             }
         }
         if (layersUpdated) {
             for (DrawListener listener : mDrawListeners) {
                 listener.drawFinished();
             }
         }
         return mCurrentViewTransform;
     }
     @WrapElementForJNI(allowMultithread = true)
     public ViewTransform syncFrameMetrics(float offsetX, float offsetY, float zoom,
                 float cssPageLeft, float cssPageTop, float cssPageRight, float cssPageBottom,
                 boolean layersUpdated, int x, int y, int width, int height, float resolution,
                 boolean isFirstPaint)
     {
         if (isFirstPaint) {
             setFirstPaintViewport(offsetX, offsetY, zoom,
                                   cssPageLeft, cssPageTop, cssPageRight, cssPageBottom);
         }
         return syncViewportInfo(x, y, width, height, resolution, layersUpdated);
     }
     @WrapElementForJNI(allowMultithread = true)
     public LayerRenderer.Frame createFrame() {
         // Create the shaders and textures if necessary.
         if (!mLayerRendererInitialized) {
             mLayerRenderer.checkMonitoringEnabled();
             mLayerRenderer.createDefaultProgram();
             mLayerRendererInitialized = true;
         }
         try {
             return mLayerRenderer.createFrame(mFrameMetrics);
         } catch (Exception e) {
             Log.w(LOGTAG, e);
             return null;
         }
     }
     @WrapElementForJNI(allowMultithread = true)
     public void activateProgram() {
         mLayerRenderer.activateDefaultProgram();
     }
     @WrapElementForJNI(allowMultithread = true)
     public void deactivateProgram() {
         mLayerRenderer.deactivateDefaultProgram();
     }
     private void geometryChanged(DisplayPortMetrics displayPort) {
         /* Let Gecko know if the screensize has changed */
         sendResizeEventIfNecessary(false);
         if (getRedrawHint()) {
             adjustViewport(displayPort);
         }
     }
     /** Implementation of LayerView.Listener */
     @Override
     public void renderRequested() {
         try {
             GeckoAppShell.scheduleComposite();
         } catch (UnsupportedOperationException uoe) {
             // In some very rare cases this gets called before libxul is loaded,
             // so catch and ignore the exception that will throw. See bug 837821
             Log.d(LOGTAG, "Dropping renderRequested call before libxul load.");
         }
     }
     /** Implementation of LayerView.Listener */
     @Override
     public void sizeChanged(int width, int height) {
         // We need to make sure a draw happens synchronously at this point,
         // but resizing the surface before the SurfaceView has resized will
         // cause a visible jump.
         mView.getGLController().resumeCompositor(mWindowSize.width, mWindowSize.height);
     }
     /** Implementation of LayerView.Listener */
     @Override
     public void surfaceChanged(int width, int height) {
         setViewportSize(width, height);
     }
     /** Implementation of PanZoomTarget */
     @Override
     public ImmutableViewportMetrics getViewportMetrics() {
         return mViewportMetrics;
     }
     /** Implementation of PanZoomTarget */
     @Override
     public ZoomConstraints getZoomConstraints() {
         return mZoomConstraints;
     }
     /** Implementation of PanZoomTarget */
     @Override
     public boolean isFullScreen() {
         return mView.isFullScreen();
     }
     /** Implementation of PanZoomTarget */
     @Override
     public RectF getMaxMargins() {
         return mMarginsAnimator.getMaxMargins();
     }
     /** Implementation of PanZoomTarget */
     @Override
     public void setAnimationTarget(ImmutableViewportMetrics metrics) {
         if (mGeckoIsReady) {
             // We know what the final viewport of the animation is going to be, so
             // immediately request a draw of that area by setting the display port
             // accordingly. This way we should have the content pre-rendered by the
             // time the animation is done.
             DisplayPortMetrics displayPort = DisplayPortCalculator.calculate(metrics, null);
             adjustViewport(displayPort);
         }
     }
     /** Implementation of PanZoomTarget
      * You must hold the monitor while calling this.
      */
     @Override
     public void setViewportMetrics(ImmutableViewportMetrics metrics) {
         setViewportMetrics(metrics, true);
     }
     /*
      * You must hold the monitor while calling this.
      */
     private void setViewportMetrics(ImmutableViewportMetrics metrics, boolean notifyGecko) {
         // This class owns the viewport size and the fixed layer margins; don't let other pieces
         // of code clobber either of them. The only place the viewport size should ever be
         // updated is in GeckoLayerClient.setViewportSize, and the only place the margins should
         // ever be updated is in GeckoLayerClient.setFixedLayerMargins; both of these assign to
         // mViewportMetrics directly.
         metrics = metrics.setViewportSize(mViewportMetrics.getWidth(), mViewportMetrics.getHeight());
         metrics = metrics.setMarginsFrom(mViewportMetrics);
         mViewportMetrics = metrics;
         viewportMetricsChanged(notifyGecko);
     }
     /*
      * You must hold the monitor while calling this.
      */
     private void viewportMetricsChanged(boolean notifyGecko) {
         if (mViewportChangeListener != null) {
             mViewportChangeListener.onMetricsChanged(mViewportMetrics);
         }
         mView.requestRender();
         if (notifyGecko && mGeckoIsReady) {
             geometryChanged(null);
         }
     }
     /*
      * Updates the viewport metrics, overriding the viewport size and margins
      * which are normally retained when calling setViewportMetrics.
      * You must hold the monitor while calling this.
      */
     void forceViewportMetrics(ImmutableViewportMetrics metrics, boolean notifyGecko, boolean forceRedraw) {
         if (forceRedraw) {
             mForceRedraw = true;
         }
         mViewportMetrics = metrics;
         viewportMetricsChanged(notifyGecko);
     }
     /** Implementation of PanZoomTarget
      * Scroll the viewport by a certain amount. This will take viewport margins
      * and margin animation into account. If margins are currently animating,
      * this will just go ahead and modify the viewport origin, otherwise the
      * delta will be applied to the margins and the remainder will be applied to
      * the viewport origin.
      *
      * You must hold the monitor while calling this.
      */
     @Override
     public void scrollBy(float dx, float dy) {
         // Set mViewportMetrics manually so the margin changes take.
         mViewportMetrics = mMarginsAnimator.scrollBy(mViewportMetrics, dx, dy);
         viewportMetricsChanged(true);
     }
     /** Implementation of PanZoomTarget
      * Notification that a subdocument has been scrolled by a certain amount.
      * This is used here to make sure that the margins are still accessible
      * during subdocument scrolling.
      *
      * You must hold the monitor while calling this.
      */
     @Override
     public void scrollMarginsBy(float dx, float dy) {
         ImmutableViewportMetrics newMarginsMetrics =
             mMarginsAnimator.scrollBy(mViewportMetrics, dx, dy);
         mViewportMetrics = mViewportMetrics.setMarginsFrom(newMarginsMetrics);
         viewportMetricsChanged(true);
     }
     /** Implementation of PanZoomTarget */
     @Override
     public void panZoomStopped() {
         if (mViewportChangeListener != null) {
             mViewportChangeListener.onPanZoomStopped();
         }
     }
     /** Implementation of PanZoomTarget */
     @Override
     public void forceRedraw(DisplayPortMetrics displayPort) {
         mForceRedraw = true;
         if (mGeckoIsReady) {
             geometryChanged(displayPort);
         }
     }
     /** Implementation of PanZoomTarget */
     @Override
     public boolean post(Runnable action) {
         return mView.post(action);
     }
     /** Implementation of PanZoomTarget */
     @Override
     public void postRenderTask(RenderTask task) {
         mView.postRenderTask(task);
     }
     /** Implementation of PanZoomTarget */
     @Override
     public void removeRenderTask(RenderTask task) {
         mView.removeRenderTask(task);
     }
     /** Implementation of PanZoomTarget */
     @Override
     public boolean postDelayed(Runnable action, long delayMillis) {
         return mView.postDelayed(action, delayMillis);
     }
     /** Implementation of PanZoomTarget */
     @Override
     public Object getLock() {
         return this;
     }
     /** Implementation of PanZoomTarget
      * Converts a point from layer view coordinates to layer coordinates. In other words, given a
      * point measured in pixels from the top left corner of the layer view, returns the point in
      * pixels measured from the last scroll position we sent to Gecko, in CSS pixels. Assuming the
      * events being sent to Gecko are processed in FIFO order, this calculation should always be
      * correct.
      */
     @Override
     public PointF convertViewPointToLayerPoint(PointF viewPoint) {
         if (!mGeckoIsReady) {
             return null;
         }
         ImmutableViewportMetrics viewportMetrics = mViewportMetrics;
         PointF origin = viewportMetrics.getOrigin();
         PointF offset = viewportMetrics.getMarginOffset();
         origin.offset(-offset.x, -offset.y);
         float zoom = viewportMetrics.zoomFactor;
         ImmutableViewportMetrics geckoViewport = mGeckoViewport;
         PointF geckoOrigin = geckoViewport.getOrigin();
         float geckoZoom = geckoViewport.zoomFactor;
         // viewPoint + origin - offset gives the coordinate in device pixels from the top-left corner of the page.
         // Divided by zoom, this gives us the coordinate in CSS pixels from the top-left corner of the page.
         // geckoOrigin / geckoZoom is where Gecko thinks it is (scrollTo position) in CSS pixels from
         // the top-left corner of the page. Subtracting the two gives us the offset of the viewPoint from
         // the current Gecko coordinate in CSS pixels.
         PointF layerPoint = new PointF(
                 ((viewPoint.x + origin.x) / zoom) - (geckoOrigin.x / geckoZoom),
                 ((viewPoint.y + origin.y) / zoom) - (geckoOrigin.y / geckoZoom));
         return layerPoint;
     }
     void setOnMetricsChangedListener(LayerView.OnMetricsChangedListener listener) {
         mViewportChangeListener = listener;
     }
     public void addDrawListener(DrawListener listener) {
         mDrawListeners.add(listener);
     }
     public void removeDrawListener(DrawListener listener) {
         mDrawListeners.remove(listener);
     }
 }

The Tor Browser / annotate

mobile/android/base/gfx/GeckoLayerClient.java@fc2d59ddac77 (annotated)

mobile/android/base/gfx/GeckoLayerClient.java